Describe the bug
Plane wave sources with a negative polar angle seem to mess up the definition of bloch boundaries. Making the polar angle the same but positive results in expected results

To Reproduce
This simulation for example:
https://tidy3d.simulation.cloud/workbench?taskId=pa-65fb5c76-4106-451f-a550-683aee990ddc

Expected behavior
This type of wave propagation

Screenshots